Draft coupling



oct. 3o, 1923. 11,472,363 A. M. MCLAMB DRAFT GOUPLING Filed April 18 1922 Patented @et 3l), i923.

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.ALEXANDER M. MCLAMB, OF LUIiIBERTON, NORTH CAROLNA.

DRAFT COUPLING.

A.Application filed April 18, 1922. Serial ."No. 554,899.

To all 107mm t may conce/ra.'

Be it known that l, UJnxANDnR M. Mo- LAMB, a citizen of the United States, residing at Lumberton, in the county of Robeson and State of North Carolina, have invented 0ertain new and useful Improvements in Draft Couplings, of which the following is a specification.

This invention relates to draft couplings and has for its object the provision of a simple device whereby a plow or other agricultural implement may be effectually connected to a tractor or a team of draft animals and by the use of which the implement will be disconnected automatically from the draft-applying instrumentality when an immovable obstruction is encountered. ln the use of agricultural implements, it frequently happens that a large root, stone, or other obstruction is met by the implement and the implement is badly damaged owing to the fact that it cannot pass the obstruction, and the halting' of the draft team cr stopping of the tractor cannot be accomplished until it is too late to avoid damage. My invention provides a coupling whereby hauling power will be effectually applied to the agricultural implement and the implement will not normally he disconnected from the draft-applying instrumentality but when an immovable obstruction is encountered, the coupling will be released and injury to the parts avoided,

In the accompanying drawings, which illustrate one embodiment of my invention,

Figure 1 is a view, partly in side elevation and partly in longitudinal section, of a draft coupling embodying my improvements;

Fig. 2 is a similar view showing the ling released;

Fig. 3 is a detail transverse section on the line 3-8 of Fig. 1.

ln carrying out my invention, l employ a har 1 which is constructed with a longil tudinal recess 2 at one` end and at its other end is slotted or notched, as indicated at 3. A clevis el or other draft-applying device is carried by the slotted end'of the draft bar 1,7and this clevis or other dra-ft device may be connected to a tractor or to whiflletrees carried by a draft team Vor to any other draft-applying instrumentality. lmmediately in rear of the slot or notch 8, a vertical opening' 5 is formed through the draft bar and in rear of the said opening, a bolt-recoupceiving opening 3 is formed through the bar. Near the rear end of the slot or notch 3, a stop 7 is extended across the same near the upper edge of the draft bar for a purpose which will presently appeal'. Extending transversely through the draft bar, near the rear end of the recess 2, are the spaced studs or pins 8, between which is received the tongue 9 extending from the lower edge of the draft lever 10, a notch 11 being formedin the lower edge of the said lever immediately in advance of the tongue 9, as clearly shown. ldlhen the device is in its normal position, as shown in F l, the lever extends longitudinally of the draft bar and forwardly over the same, the notch 11 seating upon the forward rest or transverse pin 8 and the tongue 9 extending down wardly and slightly rearwardly between the two rests or pins 8. At the upper rear corner of the lever or arm 10, l attach a link 12 which may be connected directly with a plow or other implement or may be one member of a flexible connection extending to the said implement. ln the front end of the lever or arm 10, l pivotally suspend a link 13 which carries a latch lll depending normally into the upper portion of the notch or slot 3 and engaging the rear side of the stop 7, as clearly shown in Fig. 1. rlhis latch la is constructed with a rearwardly extending finger 15 normally engaging an eye 16 at the upper end of a retainer or keeper 17. The keeper or retainer 17 is preferably in the form of a threaded rod extending through the opening 5 and equipped with nuts 18 and 19, whereby it may be adjusted relative to the draft bar. A leaf spring 20 is carried by one end of the bolt 21 which is extended through the opening G of the draft bar, and the free end of this spring 2() engages around the keeper 17 and bears against the nut 19 thereon. The force of the spring is exerted to draw the keeper downwardly through the draft bar, and this downward movement of the keeper is limited by the nut 18 thereon coming into contact with the top of the draft bar, as clearly shown, so that by properly adjusting the nut 18, the tension of the spring 2O will be regulated and, therefore, the force exerted upon the lip 15 will be controlled. A spring 22 is carried by the upper end of the bolt 21 and extends rearwardly to bear against the under edge of the lever or arm 10, as clearly shown.

Normally, the lower free end of the latch llOl lll@

lt vbears vagainst the stop 7, as shown in Fig. l, and 'the lip l5 fits lwithin the eye 16 of the keeper, and the'frictional engagement between the wall of the eye and the lip will prevent detachment of these parts. The force exerted by the spring 20 holds the latch against the stop '7 and7 therefore, exerts a'pull downwardly upon the link 13 which holds the lever or arm l() in the operative position illustrated in Fig. 1. The spring 2O acts constantly in opposition to the spring 22 so 'that the lip l5 cannot easily slip from the eye S16. Should the plow or other implement strike a large root or stone which it cannot turn aside, the draft upon the implement will be increased to such an extent that the force of the spring 2O will he overcome and the keeper 1T will be drawn upwardly by the lever 10 until the end of the latch 14: clears the stop 7 whereupon the latch will swing forwardly and the lip 15 will at once be withdrawn from the eye 16 so that the pulling force exerted upon the lever or arm l0 through the link l2 will rock the lever about the rests 8 and release it from the draft arm, as will be readily understood upon reference to Fig. 2. This described action of the lever will be effected instantly so that no damage will be caused lto the implement and no parts will be broken through the increased draft. Of course, when the coupling is released, the operator will at once become aware of the fact and will stop the tractor or the draft team. After the implement has been cleared of the obstruction, the coupling can be readily returned to its normal condition inasmuch as the latch will be still carried by the lever, and it will be necessary merely to engage the tongue 9 between the rests or pins 8, as indicated in Fig. 2, and then rock the lever downwardly and forwardly so .that the latch may be again set in the position shown in Fig. l. Y

My device is exceedingly simple in the construction and arra ngementV Vof its Vparts and will act'instantly when necessity arises, although normally it will effectually couple the implement with the hauling instrumentality.

Having thus described the invention, what is claimed as new is:

l. ln a draft coupling, the combination of a draft bar7 a draft lever extending longitudinally of and releasably engaged at one end with the draft bar, a latch `freely suspended upon the opposite end of the draft lever, a keeper 0n the draft bar, a stop on the draft bar, 'the free end of the latch normallybearing against the rear side of the stop, a linger v.projecting rearwardly from the latch and engaging the keeper, andVV yieldable means upon the draft bar tending constantly to release the lever from the draft bar.

2. In a draft coupling, the combination of a draft bar, a stop on the draft bar, a draft lever releasably engaged with the draft bar, a spring carried by the ldraft bar and hearing upon the lever and tending constantly to release the same from the'draft bar, a latch suspended on the draft lever` and nornially engaging` the stop on the draft bar, a keeper movably mounted on the draft bar and engaging the latch, yieldable means acting on the keeper to maintain it in engage` ment with the latch but permit it under abnormal strains to release the latch, and adjustable means for limiting the movement of the keeper in one direction.

Intestimony whereof I affix mv signature.

ALEX. M.; MCLM. [Ls] 

